[Reviewer Andy] Dynamic Sproutlet loading

Andy

Can you review the changes for dynamic sproutlet loading.  I'll email updated spec separately.

Mike
I think this a rehash of a discussion we had many, many weeks ago over memento architecture.  I agree with Andy on this (we have broken our SOA model) but the ship has sailed so I'm not going to fix it here.

I did raise with Matt whether there were requirements to have higher level packages other than sprout and he felt it wasn't necessary.